Considering a lot of people use trains in India, train tickets tend to be cheap, depending on class of travel, of course.

What I am interested in is finding out which train ride or which route (since there can be different types of trains on the same route) has the most expensive one way ticket for each of the following classes - General compartment, Sleeper class, any of the AC classes (it will most likely be 1AC but perhaps I'm wrong) and finally AC chair or any other uncommon class.

As a bonus question I'd like to get a list of deluxe tourist trains such as Palace on wheels and prices for those trains.

Try not to make this such a broad list type question. You are asking way too much here. Secondly, all normal trains in India are charged according to distance, so the costliest ones are mostly likely the longest ones.
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Ankur Banerjee♦Apr 28 '12 at 23:58

Its not the Indian government website:IRCTC is a private company in which government has some stake. It provides a UI portal for the inventory and booking process for the Agents and travelers. The railway has its own system for providing inventories and booking statuses which is integrated with IRCTC. The Indian railway cannot(does not want to) directly provide the same to the end users.
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user2320May 2 '12 at 4:55

There are some exceptions, such as 'Garib Raths' where the air-conditioned fares are lower than those of 'Express' or 'Mail' trains, but by and large this list shows the hierarchy of trains.

Within a specific hierarchy (such as 'Express') and for a specific fare class such as 'sleeper' or 'third sleeper', the fare is proportional to distance. This implies that for 'regular' trains, the most expensive fare simply depends upon the distance. This can be found from the list of longest train journeys in India.

Trains in India are a pure nostalgia; reminiscent of summer holidays, vacations, bittersweet memories, and family bonding over extended trips while traveling across the nation. There’s something exciting about the journey, more than the destination.

Maharajas' Express, is one of the Most Expensive Trains in India.
For 8 days this pan Indian train takes guests on a ride across the best and the most prominent destinations of the country - Taj Mahal, the Khajuraho temples, wildlife environs of Ranthambore, Fatehpur Sikri and the holy bathing Ghats of Varanasi. The cheapest rate per person per day is a whopping US$ 800 for a Deluxe cabin. The next two slabs are US$ 900 and US$ 1,400. And the Presidential Suite comes for US$ 2,500.
The Maharajas' Express will have 88 passengers (a normal III AC coach packs in 72) living in suites fit for a prince. All food and drinks are complimentary.

Indian Splendour is a 8 Days / 7 Nights one-way journey from Delhi to Mumbai, which covers Delhi-Agra-Ranthambore-Jaipur-Bikaner-Jodhpur-Udaipur-Balasinor-Mumbai.
The adult fare starts at USD $5560 for a Deluxe Cabin Twin/Double.